untreated

adjective

un·​treat·​ed ˌən-ˈtrē-təd 

: not treated

untreated wastewater

especially : not improved or controlled medically

an untreated case of pneumonia

untreated diabetic patients

Synonyms

• crude
• native
• natural
• raw
• rude
• undressed
• unprocessed
• unrefined

Examples of untreated in a Sentence

untreated wool

Recent Examples on the Web

The disease itself is not deadly, but left untreated, the antibodies can infiltrate different parts of the body like the pancreas, lung or liver. —David Oliver, USA Today, 23 Apr. 2025

But if left untreated, carbon monoxide poisoning can lead to heart attacks, brain injury, and death.5 How Does Carbon Monoxide Poisoning Happen in Hotels? —Cathy Nelson, Health, 11 Apr. 2025

Atrial fibrillation is a common type of irregular heart rhythm, and leaving it untreated can lead to a stroke. —Eloy Geenjaar, The Conversation, 10 Apr. 2025

Left untreated, cavities can raise the risk of malnourishment, lower self esteem, and lead to abscess and more serious infections. —Lauren Leffer, Popular Science, 9 Apr. 2025

Word History

First Known Use

15th century, in the meaning defined above

Rhymes for untreated

• accreted
• competed
• completed
• conceited
• concreted
• defeated
• deleted
• depleted
• entreated
• intreated
• maltreated
• mistreated

Medical Definition

untreated

adjective

un·​treat·​ed -ˈtrēt-əd 

: not subjected to treatment

an untreated disease